Merge two dict object deeply

dict_utils.py

#!/usr/bin/env python
def merge_dict(data, target):
    for key, value in data.iteritems():
        node = target.get(key)
        if not node or type(value) != type(node):
            target[key] = value # add new value or replace value when type conficts
            continue
        if isinstance(value, dict):
            merge_dict(value, node) # iterate merge dict-type value
            continue 
        if isinstance(value, list):
            for item in value: # merge list-type value
                if not node.__contains__(item): node.append(item)
        else:
            target[key] = value # replace value for simple type